In recent years, the development of small, powerful, battery powered electric motors has led to the production of a number of diverse, cordless tools. Attempts have been made to design cordless power saws, but a number of previously insurmountable problems have limited cordless power saw development to small coping and saber saws of the types shown by U.S. Pat. Nos. 4,555,849 to Ando et al. and 4,949,464 to Adomatis.
A powerful, cordless hand saw capable of cutting metal, hard wood, plastic or other hard objects must have a reciprocal stroke which is much longer than the short, vibratory stroke of smaller coping and saber saws. Most high torque rotary drive motors generally rotate at speeds which are too fast to permit a smooth transition to a relatively long stroke, reciprocal motion without creating considerable vibration which is undesirable in a hand saw. Additionally, this transition must be effectively made within a very limited area to control the size and bulk of the resultant tool.